Class A Surface Waters RSA485A9

New Hampshire began classifying its surface waters in 1948, with classifications now established by state legislation under RSA 485-A:9 and RSA 485-A:10. Before 1991, waters were categorized as Class A (highest quality, suitable for water supply), Class B (acceptable for recreation and treated water supply), or Class C (suitable for fishing, boating, and industrial use). In 1991, HB 560-FN reclassified all Class C waters to Class B, aligning state goals with the Clean Water Act’s fishable/swimmable standards. Since then, all surface waters in New Hampshire have been classified as either Class A or B, with most being Class B. To support this classification system, a Geographic Information System (GIS) dataset has been developed, linking geo-spatial data to legislative records for improved accessibility and reference.